The experimental spaceship won’t have any people on board, but it will ferry a spacesuit-clad dummy and some cargo to the the US$150 billion orbiting laboratory. If this test proves successful, SpaceX may launch its first astronauts as soon as July.

“Demo-1 is a flight test, it absolutely is, although we view it also as a real mission, a very critical mission,” Kirk Shireman, who manages the space station program at NASA’s Johnson Space Center, said during a press briefing about the upcoming launch.

“The ISS still has three people on board, and so this vehicle coming up to the ISS for the first time has to work. It has to work.”

Demo-1 is part of a roughly US$8 billion effort by NASA called the Commercial Crew Program, which aims to restore NASA’s ability to launch astronauts on its own ships.

The agency has not had a way to do that since it retired the last space shuttle in July 2011. (US astronauts currently fly to and from the ISS on Russian Soyuz spacecraft.)

Saturday’s launch would mark the first launch of an American-made spaceship for astronauts since then.

“Additional launch readiness reviews today from NASA’s Commercial Crew Program, space station team, and SpaceX’s launch team concluded the teams are still ‘go’ for launch of the first uncrewed test flight of the Crew Dragon on a mission to the International Space Station,” Stephanie Martin, a NASA spokesperson, wrote in a blog post on Wednesday.

(SpaceX)

How to watch SpaceX’s Crew Dragon launch live online

NASA TV plans to broadcast live video and commentary of the Falcon 9 rocket launch starting at 2am ET on March 2. You can watch it using the embedded player below. SpaceX may also stream its own webcast of the launch.

But first, the weather must cooperate. On Thursday morning, the US Air Force released a weather forecast suggesting there will be a roughly 20 percent chance of delay due to cloud cover that is too thick to launch a rocket within NASA’s margins of safety.

“Lingering moisture may lead to stubborn cloud cover sticking around for much of the day Friday,” the report said, noting that those clouds could lead SpaceX and NASA to delay the launch if they linger too long.

The backup launch date is Tuesday, March 2, though the forecast for Tuesday is markedly worse. The USAF weather report says there could be a 40 percent chance of delay then, due to 100 mph (160 km/h) winds in the upper atmosphere.